Bluetooth GATT Characteristic Reference
Uncertainty (0x2AB4)
The Uncertainty characteristic describes the uncertainty of the location information the device exposes.
Quick Summary
Payload length is 1 bytes. This page is generated from official GATT XML and presented as implementation-ready guidance.
At a Glance
Key reference details for BLE implementation, interoperability testing, and AI-assisted troubleshooting.
| Property | Value |
|---|---|
| Name | Uncertainty |
| UUID | 0x2AB4 |
| Type | org.bluetooth.characteristic.uncertainty |
| XML Root | Characteristic |
| Source File | org.bluetooth.characteristic.uncertainty.xml |
| Field Count | 1 |
Field Specification
Parsed field definitions from the source XML value structure.
| Field | Requirement | Format | Unit | Exponent | Notes |
|---|---|---|---|---|---|
| Uncertainty | Mandatory | uint8 | - | - | - |
Bit Map
Bit-level enumerations extracted from the XML BitField definition.
| Field | Bit | Size | Name | 0 Means | 1 Means |
|---|---|---|---|---|---|
| Uncertainty | 0 | 1 | Stationary | stationary | mobile |
| Uncertainty | 1 | 3 | Update Time | upto 3s | upto 4s |
| Uncertainty | 4 | 3 | Precision | less than 0.1m | 0.1-1m |
Byte Layout and Decode
Payload length is 1 bytes.
function decodePayload(dataView, offset = 0) {
const uncertainty = dataView.getUint8(offset + 0);
return { uncertainty };
}Use Cases and Integration Notes
BLE Telemetry
Map characteristic values into dashboards and alerts for device observability.
Firmware Regression
Compare decoded fields across builds to detect protocol or scaling changes.
App Integration
Build stable parsing paths that convert raw payloads into typed app models.
Implementation Checklist
- Validate payload length and mandatory fields before decode.
- Decode with Bluetooth-specified signedness, unit, and exponent handling.
- Convert units at presentation boundaries to avoid drift in business logic.
- Persist raw packets and decoded values for reproducible troubleshooting.
FAQ
What is Uncertainty in Bluetooth GATT?
Uncertainty is defined as a Bluetooth GATT characteristic entry with type org.bluetooth.characteristic.uncertainty and UUID 0x2AB4.
What UUID identifies Uncertainty?
The UUID for Uncertainty is 0x2AB4.
How should I parse Uncertainty?
Payload length is 1 bytes.
Where does this definition come from?
This page is generated from the Bluetooth SIG mirror XML in the oesmith/gatt-xml repository.
How does this page support BLE implementation?
The page combines structured tables, practical Q&A, and JSON-LD metadata to help teams validate integrations and troubleshoot consistently.